Di- and tripentaerythritol esters of isostearic acid

Abstract

Dipentaerythritol and tripentaerythritol esters of isostearic acid are disclosed. The polyol ether esters of this invention exhibit low volatility and good oxidative and thermal stability and are useful lubricants for high temperature applications.

We claim: 
     
       1. A polyol ether ester having a hydroxyl value less than 10, flashpoint greater than 500° F. and pour point less than 20° F. comprising the reaction product of a molar excess of isostearic acid, obtained as a by-product from the manufacture of polymer fatty acids from naturally occuring unsaturated C 18  fatty acids, and a polyol ether of pentaerythritol having from 6 to 8 hydroxyl groups and containing at least 85 percent by weight dipentaerythritol, tripentaerythritol and higher oligomers and less than 15% by weight monopentaerythritol. 
     
     
       2. A polyol ether ester according to claim 1 wherein the isostearic acid contains 25 percent or less straight-chain fatty acids. 
     
     
       3. A polyol ether ester according to claim 2 wherein the ratio of dipentaerythritol to tripentaerythritol is in the range 9:1 to 1:9 and the monopentaerythritol content is less than 10 percent. 
     
     
       4. Dipentaerythritol hexaisostearate. 
     
     
       5. Tripentaerythritol octaisostearate.